Since an automated manual transmission, such as a DCT or an AMT, controls the driving of a vehicle through clutch control after gear engagement, the transmission predicts a gear selection and controls the engagement of gears for non-driven shafts.
However, the transmission controls the vehicle such that the gears wait rather than become engaged in advance before the vehicle is stopped in order to reduce noise when the gears are engaged. When it is intended to stop the vehicle by changing a shift lever from a second gear position to a reverse gear position during forward movement of the vehicle, second gear must be disengaged and the reverse gear must then be engaged. For this reason, the gears on both shafts may be disengaged simultaneously.
In this case, when the vehicle has an output shaft speed sensor, the speed and forward/backward movement of the vehicle may be determined using the output shaft speed sensor even though the gears on both shafts are simultaneously disengaged. Therefore, there is no problem relating to control of the vehicle.
However, when the vehicle has only an input shaft speed sensor and no output shaft speed sensor, the speed and forward/backward movement of the vehicle have to be determined using the input shaft speed sensor. Therefore, since the speed and forward/backward movement of the vehicle may not be adequately determined when the gears on both shafts are disengaged simultaneously, there can be a problem relating to a control of the vehicle.
In particular, if a wheel speed sensor has failed or a related controller malfunctions such that signals indicative of vehicle speed are not transmitted thereto, it may be impossible to determine the state of the transmission when the gears on both shafts are disengaged simultaneously.
The foregoing is intended merely to aid in the understanding of the background of the present disclosure, and is not intended to mean that the present disclosure falls within the purview of the related art that is already known to those skilled in the art.